from DateTime import DateTime

for r in context.portal_catalog():
    date1 = expires                 #the expiration date
    date2 = context.ZopeTime()      #the current date
    t = int(date1.earliestTime()-date2.earliestTime())  #the integer difference between dates
    x = r.getObjec()                #gets object via catalog

    if t==XX:                 #if there is XX days between dates...
      contentObject = r.getObject()                                 
      objectHistory=contentObject.portal_workflow.getInfoFor(contentObject, 'review_history')
      thisRevision=objectHistory[-1]
      nowDate=thisRevision['time'].aCommon()
      authorComment=thisRevision['comments']
          
      mailList=[]
      try:
        mailhost=getattr(context, context.portal_url.superValues('Mail Host')[0].id)
      except:
        raise AttributeError, "Cannot find a Mail Host object"
      mMsg = 'An item you created on the website is nearing expiry.\n\nPlease update the item.\n\nThis email was generated and sent by the website.\n\n'
      mMsg += 'Title: ' + contentObject.TitleOrId() + '\n\n'
      mMsg += 'Description: ' + contentObject.Description() + '\n\n'
      mMsg += contentObject.absolute_url() + '\n'
      mMsg += 'Author comment:' + authorComment + '\n\n'
      mTo = context.portal_membership.getMemberById(contentObject.Creator()).email
      mFrom = 'Webmaster@acme.com'
      mSubj = 'Website item nearing expiration date'

      mailhost.send(mMsg, mTo, mFrom, mSubj)       #send email to author

    elif t==0:         #else if expiration date=today's date
      if x.review_state!="private":              #change review_state to private via expire transaction
        try:
          context.portal_workflow.doActionFor(contentObject,'expire')
        except:
           print 'didnt change state'
return printed